ABSTRACT
Analysis of linear circuits rests on two fundamental physical laws that describe how the voltages and currents
in a circuit must behave. This behavior results from whatever voltage sources, current sources, and energy
storage elements are connected to the circuit. A voltage source imposes a constraint on the evolution of the
voltage between a pair of nodes; a current source imposes a constraint on the evolution of the current in a
branch of the circuit. The energy storage elements (capacitors and inductors) impose initial conditions on
currents and voltages in the circuit; they also establish a dynamic relationship between the voltage and the
current at their terminals.
